In our discussion, IceCube “shower” events with energies above 60 TeV and “track” events with energies above 30 TeV are analyzed. 12 of 24 shower events and 12 of 15 track events can be associated with GRB candidates, which indicates that a part of these IceCube ultra-high energy neutrinos are emitted from the GRB source. The sources of ultra-high energy neutrinos might have more possibilities. As an example, some researches indicate that two ultra-high energy neutrinos might be emitted by blazars [1]}, [2]}, [3]}. Such a small number of neutrino events associated with blazars does not conflict with the results to attribute GRBs as a significant source for IceCube TeV and PeV events [4]}, [5]}.
